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' (No Model.) I

G. M. GITHENS.

ROCK DRILL.

Patefited 001;. 4.1881.

UNITED STATES PATENT OFFICE.

GEORGE M. GI'IHENS, OF BROOKLYN, E. D., NEW YORK.

ROCK-DRILL.

SPECIFICATION formiz1;g\pa.rt of Letters Patent No. 247,819, dated October 4, 1881.

Application filed May 16, 1881. (No model.)

To all whom it may concern.-

Be it known that I, GEORGE M. GITHENs, of Brooklyn, E. D., in the county of Kings and State of New York,'have.invented an Improv ement in Rock-Drills, of which the followingis a specification.

Rock-drills have been driven by steam or compressed air acting within a cylinder upon a piston that is connected with the drill, and in these machines the cylinder has been moved along for feeding by the action of a screw, and the screw has been operated upon by the piston acting against a tappet and giving amovement to a rodor lever that is provided with a pawl thatmoves a ratchet-wheel attached to the nut of the screw. In this instance the pawl and ratchet-wheel are liable to injury, because there isia very sudden movement given by the piston, and the inertia of the parts has to be overcome.

' My improvement is for overcoming this difficulty, and it relates to a means for simply unlatching the screw or nut, instead of turning it, and then allowing the movement of thecylinder endwise to cause the rotation of the screw or nut by the inclined-plane action. This allows a more gradual movement. of the parts. It prevents the severe concussion onthe pawl and ratchet-teeth, and itinsures greater durability in the parts, and amore uniform feeding movement.

In the drawings, Figure l is a longitudinal section of the cylinder and valve and elevation of the piston and screw. Fig. 2 is an end view of the cylinder, and Fig. 3 shows the pawl for holding the screw from turning backwardly.

The cylinder a,piston b, drill-holding pistonrod 0, and valve 01 are of any usual character.

My Patent No. 212,598 describes a valve somewhat similar to that represented herein. Any novelty in the presentvalve I reserve for a separate application. I also remark that the piston and drill are partially revolved between each stroke,soasto cause the drill to strike properly upon the rock, and for this purpose any suitable device is employed. The screws is for feeding the cylinder along as the drilling pro-' grosses. In some machines the nut f is at the cylinder, and the same is revolved, the screw remaining stationary. In other machines the screw is revolved by hand and the nut remains axis ofthe cylinder.

stationary. If the nutis held by the frame or legs that support the' parts in position, the same may be provided with a pinion and crank, by means of which the not can be turned back to run the cylinder and drill away from the .in' the supports of the drill,then the partfwill represent a head or hub upon the screw, and

formed as one piece therewith or permanently connected, and the locking-wheel kwill be a I part thereof.

The rock-shaft Z passes along parallel to the At its inner end there is a foot, n'aagainst one side'of which the incline or tapering portion of the piston 1) acts to partially turn the rock-shaft l.

n is an arm on the shaft 1 outside the cylinder, and 0 is a blocking-pawlhinged to its end.

The spring p presses the swinging end of n I and the pawl 0 toward the blocking-wheel k.

This blocking-wheel has one, 'two, or more notches around its periphery adapted to receive the endof the pawl 0. Aninclined stud, r, is at the back of the blocking-pawl 0, and there is a spiral or other spring, o, therein.

When the rock-drilling is progressing the cylinder at is presumed to remain immovable and the piston and rod reciprocate. When the drilling has progressed sufficiently for the incline upon the piston to touch the toe m and turn the rock-shaft the pawl 0 will be drawn back out of contact with the blocking-wheel, and the spring '2; will move such pawl 0 away from the stud r, so that the pawl 0 cannot reenter the notch in the wheel 70. The wheel k is now free to turn, and the steam or air act ing in the cylinder to raise the piston and drill also acts to move the cylinder toward the rock, and the incline of the nut and screw will move againsteach other, causing the rotation or partial rotation of the wheel 70 and screw or nut, and thereby allowing the cylinder to move until arrested by the pawl o entering the next allows the piston to move until it again strikes the toe m and withdraws the blocking-pawl, and the operations are repeated.

In some instances I make useof a compound conical incline around the piston, as at 2 and 8, the portion 2 operating the valve and the portion 3 operating the toe m, as the toe will not project into the cylinder as much as does the valve; hence the part 3 will act either on the valve or the toe and the part 2 will only act on the valve. The part 3 should only extend about half around the piston, and therefore the toe can only be operated upon during that portion of the rotary and reciprocating movement of the drill and the piston when said part 3 is adjacent to the toe m, and the feed cannot take place oftener than once each revolution of the drill.

In operating all rock-drills by direct action of steam, the tendency of the pressure is to move the cylinder in one direction, and the piston and drill in the other direction; and this produces a violent concussion of the screw endwise upon the nut, or of the nut upon the screw, if the thread has worn loose. To prevent this undesirable movement 1 employ a selfacting lock-nut. 10, that surrounds the screw. It is made of steel, and as the screw or nut is shaken endwise by the reciprocations this nut acts by gravity, and, sliding down the incline of the screw, intervenes as a wedge, to prevent end movement and looseness. This lessens wear by preventing end movement and concussion, and when applied to screws already worn loose, it allows them to be kept in use much longer before the screw is worn out.

In most instances it isimportant to prevent the screw or the nut turning back the wrong way when the blocking-pawl is liberated, and also to prevent any tendency to press back the blocking-pawl by the inclined portion of the notches in the wheel It. To provide for this a ratchet-wheel, w, and holding-pawl t are applied to the screw or nut, as seen in Figs. 1

and 3. A friction-clamp or any similar means may be substituted for the holding-pawl.

A lever may take the place of the rock-shaft and arm, such lever having the toe at one end and being connected to the locking-pawl at the other end.

I claim as my invention- 1. The combination, with the cylinder and piston in a rock-drill, of a screw and nut, a blocking-wheel, and apawl or latch, and means for withdrawing such pawl or latch, so as to allow the screw or not to turn by the endwise movement of the cylinder as acted upon by the power, substantially as set forth.

2. The combination, in a rock-drill, of the cylinder a, piston b, toe m, rock-shaft l, arm n, blocking-pawl 0, wheel k, screw, and nut, sub stantially as set forth, whereby the blockingpawl is moved out of action by the piston, for the purposes specified.

3. The combination, with the screw and nut in a rock-drill, of a notched blocking-wheel, pawl or latch mechanism for withdrawing the same, and a spring to prevent the pawl or latch immediately re-entering the notch in the wheel, substantially as set forth.

4. The combination, with the screw and nut in a. rock-drilling machine, of a loose wedgeacting lock-nut, for the purposes and as set forth.

5. The combination, with the screw and nut in a rock-drilling machine, of a rock-shaft and toe or their equivalents, and a piston having an incline on its surface extending partially around it to act upon the too when the piston is turned into the proper position, the piston not acting on the tappet during a portion of .its revolution, substantially as set forth.

Signed by me. this 4th day of May, A. D. 1881.

GEO. M. GITHENS.

Witnesses GEO. T. PINGKNEY, WILLIAM G. MOTT. 

